#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e6+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
char str[maxn];
LL d[maxn];
inline int solve(){
    int n=strlen(str);
    int i=1;int j=0;
    while(i<n){
        if(str[i]==str[j]){
            d[i++]=++j;
        }
        else{
            if(j>0) j=d[j-1];
            else j=0,i++;
        }
    }
    return n-d[n-1];
}
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL n;cin>>n;
    cin>>str;
    cout<<solve()<<endl;
   	return 0;
}
